There are numerous reports that former U.S. president Jimmy Carter will travel to North Korea on a "private" mission to free a Korean-American man detained there.

Speaking to reporters Monday, White House spokesman Josh Earnest said Mr. Carter is making the North Korea trip in his "personal capacity." But later the White House issued a statement saying it was not confirming the reported Carter trip.

A Carter spokeswoman said the former president was in the Colombian capital, Bogota, on Monday, as part of a mission to "announce success in the fight against river blindness disease." She also said Carter has no "immediate" plans to travel to North Korea.

Kenneth Bae being interviewed by Japanese pro-North Korea newspaper Choson Sinbo at North Korean labor camp, June 26, 2013.

Seeking Bae's release

Earlier Monday, the South Korean news agency Yonhap said Carter will visit Pyongyang soon to urge that North Korean leaders release Kenneth Bae.

North Korea detained Bae, a tour operator, in the northeastern port of Rason last November. He was later convicted of trying to topple the government and was sent to a prison camp to serve 15 years of hard labor.

The Internet petition website Change.org said Bae's family had no immediate response to the reports about Mr. Carter. The family launched a campaign on Change.org in early May, calling on the Obama administration to do everything it can to secure an amnesty for Bae and allow him to return home to his family and friends.

The former U.S. president has visited the impoverished country several times in recent years, despite the lack of diplomatic relations between Pyongyang and Washington. The two sides have yet to sign a peace treaty since the Korean War ended in 1953.

Diplomacy with Pyongyang

Carter first traveled to North Korea in 1994, when he met then-Supreme Leader Kim Il Sung to defuse a nuclear crisis triggered by Pyongyang's expulsion of international nuclear inspectors.

Carter traveled again to North Korea in August 2010 and secured the release of Aijalon Mahli Gomes, another American citizen who had been sentenced to hard labor on charges of entering the country illegally. The former president last visited Pyongyang in April 2011 as part of an international group of former statesmen and women, known as The Elders.

Bae recently urged the U.S. government to secure his release, saying he is in poor health and wants to be reunited with his family. He made the emotional appeal from prison as he spoke in Korean in a videotaped interview granted to the Japanese newspaper Choson Sinbo, which is sympathetic to Pyongyang.

The newspaper published the interview on July 3 and said it was conducted on June 26 with North Korean government approval.